Fine case in which footballers might be seen? (7,3)
I believe the answer is:
penalty box
'in which footballers might be seen?' is the definition.
'fine case' is the wordplay.
'fine' becomes 'penalty' (I've seen this before**).
'case' becomes 'box' (boxing is a kind of casing).
'penalty'+'box'='PENALTY BOX'
(Other definitions for penalty box that I've seen before include "Spot container" , "area spotted?" .)